638748995 has 16 divisors (see below), whose sum is σ = 787851360. Its totient is φ = 496953600.

The previous prime is 638748991. The next prime is 638748997. The reversal of 638748995 is 599847836.

It is not a de Polignac number, because 638748995 - 2² = 638748991 is a prime.

It is a super-2 number, since 2×638748995² = 816000557227020050, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (638748991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15380 + ... + 38910.

It is an arithmetic number, because the mean of its divisors is an integer number (49240710).

Almost surely, 2^638748995 is an apocalyptic number.

638748995 is a deficient number, since it is larger than the sum of its proper divisors (149102365).

638748995 is a wasteful number, since it uses less digits than its factorization.

638748995 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23686.

The product of its digits is 13063680, while the sum is 59.

The square root of 638748995 is about 25273.4840297099. The cubic root of 638748995 is about 861.2120079747.

The spelling of 638748995 in words is "six hundred thirty-eight million, seven hundred forty-eight thousand, nine hundred ninety-five".